
import java.util.*;
class Example2_5 {
    public static void main(String args[]) {
        int start = 0,end,middle;
        int a[] = {12,45,67,89,123,-45,67};
        int N = a.length;
        for(int i=0; i<N; i++) {
        for(int j = i+1; j < N;j++){
            if(a[j] < a[i]){
              int t = a[j];
              a[j] = a[i];
              a[i] = t;
            }
          }
        }
        Scanner scanner = new Scanner(System.in);
        System.out.println("输入整数，程序判断该整数是狗在数组中：");
        int number = scanner.nextInt();
        int count = 0;
        end = N;
        middle=(start+end)/2;
        while(number!=a[middle]){
            if(number>a[middle])
               start = middle;
            else if(number<a[middle])
               end = middle;
            middle = (start+end)/2;
            count++;
           if(count>N/2)
             break;
        }
        if(count>N/2)
          System.out.printf("%d不在数组中.\n",number);
        else
           System.out.printf("%d在数组中.\n",number);
     }
}

